An ultrahazardous activity in the common law

Common law

Common law is law developed by judges through decisions of courts and similar tribunals rather than through legislative statutes or executive branch action...

 of torts is one that is so inherently dangerous that a person engaged in such an activity can be held strictly liable for injuries caused to another person, even if the person engaged in the activity took every reasonable precaution to prevent others from being injured. In the Restatement of the Law

Restatement of the Law

In American jurisprudence, the Restatements of the Law are a set of treatises on legal subjects that seek to inform judges and lawyers about general principles of common law...

 2d, Torts 2d, the term has been abandoned in favor of the phrase "inherently dangerous activity."

Categories of ultrahazardous activity

There are several categories of activities which are commonly recognized as being ultrahazardous, and therefore subject those who engage in them to strict liability. These include:

• Transportation, storage, and use of dynamite
  Dynamite
  Dynamite is an explosive material based on nitroglycerin, initially using diatomaceous earth , or another absorbent substance such as powdered shells, clay, sawdust, or wood pulp. Dynamites using organic materials such as sawdust are less stable and such use has been generally discontinued...
  
   and other explosives
• Transportation, storage, and use of radioactive materials
• Transportation, storage, and use of certain hazardous chemicals
• Keeping of wild animals
  Wildlife
  Wildlife includes all non-domesticated plants, animals and other organisms. Domesticating wild plant and animal species for human benefit has occurred many times all over the planet, and has a major impact on the environment, both positive and negative....
  
   (i.e. animals that are not normally domesticated in that area)
  • Note that in this context domesticated does not merely refer to animals that are commonly bred and raised in captivity, such as alligator
    Alligator
    An alligator is a crocodilian in the genus Alligator of the family Alligatoridae. There are two extant alligator species: the American alligator and the Chinese alligator ....
    
    s.
• Keeping of domesticated animals that have a known propensity for dangerous behavior (e.g., keeping a dog
  Dog
  The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
  
   that has attacked people before)

A person who is injured by one of these ultrahazardous activities while trespassing on the property

Property

Property is any physical or intangible entity that is owned by a person or jointly by a group of people or a legal entity like a corporation...

 of the person engaged in the activity is barred from suing under a strict liability theory. Instead, they must prove that the property owner was negligent.

In the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, this area of law is governed by the rule established in Rylands v Fletcher

Rylands v Fletcher

Rylands v Fletcher [1868] was a decision by the House of Lords which established a new area of English tort law. Rylands employed contractors to build a reservoir, playing no active role in its construction. When the contractors discovered a series of old coal shafts improperly filled with debris,...

.

Determining if an activity is ultrahazardous

Factors determining an activity is ultrahazardous:

1. The relative possibility of harm.
2. The level of seriousness of potential harm.
3. The level of activity most persons would not regularly engage in ultrahazardous activities.
4. If the possibility of harm is decreased with the utmost care.
5. Whether the risk of the activity outweighs its social value.
6. Inappropriateness of the activity in the area it is commenced.